PIC17C42 Microchip Technology, PIC17C42 Datasheet - Page 139

• Manufacturer Part Number: PIC17C42
• Description: High-Performance 8-Bit CMOS EPROM/ROM Microcontroller
• Manufacturer: Microchip Technology

TABLWT
Example1:
Example 2:
1996 Microchip Technology Inc.
Before Instruction
After Instruction (table write completion)
Before Instruction
After Instruction (table write completion)
Program
Memory
16 bits
REG
TBLATH
TBLATL
TBLPTR
MEMORY(TBLPTR)
REG
TBLATH
TBLATL
TBLPTR
MEMORY(TBLPTR - 1) =
REG
TBLATH
TBLATL
TBLPTR
MEMORY(TBLPTR)
REG
TBLATH
TBLATL
TBLPTR
MEMORY(TBLPTR)
Table Write
TABLWT
TABLWT
15
15
TBLPTR
TBLAT
8
0, 1, REG
1, 0, REG
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
7
0x53
0xAA
0x55
0xA356
0xFFFF
0x53
0x53
0x55
0xA357
0x5355
0x53
0xAA
0x55
0xA356
0xFFFF
0x53
0xAA
0x53
0xA356
0xAA53
0
0
Memory
8 bits
Data
TLRD
Syntax:
Operands:
Operation:
Status Affected:
Encoding:
Description:
Words:
Cycles:
Q Cycle Activity:
Example:
Before Instruction
After Instruction
Before Instruction
After Instruction
Program
Memory
16 bits
Decode
t
RAM
TBLAT
RAM
TBLAT
t
RAM
TBLAT
RAM
TBLAT
Q1
=
=
=
=
=
=
=
=
=
=
TBLATH or
Table Latch Read
[ label ] TLRD t,f
0
t
If t = 0,
If t = 1,
None
Read data from 16-bit table latch
(TBLAT) into file register 'f'. Table Latch
is unaffected.
If t = 1; high byte is read
If t = 0; low byte is read
This instruction is used in conjunction
with TABLRD to transfer data from pro-
gram memory to data memory.
1
1
TLRD
TBLATL
register
Read
1010
Q2
TBLATL
TBLATH
0
?
0x00AF
0xAF
0x00AF
1
?
0x00AF
0x00
0x00AF
[0,1]
f
15
15
255
TBLPTR
PIC17C4X
TBLAT
8
t, RAM
00tx
(TBLATH = 0x00)
(TBLATL = 0xAF)
(TBLATH = 0x00)
(TBLATL = 0xAF)
(TBLATH = 0x00)
(TBLATL = 0xAF)
(TBLATH = 0x00)
(TBLATL = 0xAF)
7
Execute
f;
f
Q3
DS30412C-page 139
0
0
ffff
register 'f'
Memory
8 bits
Data
Write
Q4
ffff